The use of hydrogen as a possible fuel source for a wide range of devices has prompted much research into hydrogen storage and delivery technologies. One current hydrogen storage approach involves the use of storage tanks that contain one or more metals (including alloys) capable of reacting with gaseous hydrogen to reversibly form metal hydride compounds. The reversible storage and release of hydrogen gas by way of metal-hydride forming metals enables hydrogen to be stored in greater quantities per unit volume than is normally possible by storing hydrogen gas in a pressurized vessel under standard hydrogen storage conditions. A particular goal of this hydrogen storage technology, moving forward, is to store useful amounts of hydrogen so that a hydrogen-consuming device can be operated over a sufficient period of time without the need to constantly replenish its hydrogen fuel reserves. Efforts are also currently underway to try and supply hydrogen gas to a hydrogen-consuming device at modest temperature and pressure conditions in order to eliminate some rather complex and expensive auxiliary equipment that may otherwise be needed.
The sorption of hydrogen gas to form metal hydride compounds is generally an exothermic reaction that often requires the removal and dissipation of at least some of the heat generated so that further hydrogen sorption is not inhibited. Conversely, the desorption of hydrogen gas from the metal hydride compounds is generally an endothermic reaction that may require a fast and/or continuous input of heat to drive the reaction and liberate hydrogen gas at a sufficient rate. The ability to effectively transfer heat to and from the metal hydride compounds is thus a factor that contributes to their overall bulk hydrogen storage capacity and, in turn, directly impacts the frequency at which hydrogen gas must be re-charged to the tank or vessel containing the metal-hydride compounds.
The development of improved hydrogen storage materials for the storage of hydrogen gas is therefore currently in demand.